Thought I'd throw this out there. When I bought my TQ Thrust D's they just came out with the D in a 16" wheel, but I could only get them in 16 x 8 w/ 4" backspace. The rear clears, close but works, the front with a 2" drop rubs, especially with other people in the car, I have to be very carefull. I believe the wheel deminsions from your 66 is very similar to the 68/69s.

Now, im looking into getting custom D's made in 16 x 7 4"

You can probably squeeze a 9" wide wheel and tire in the back with the 4 3/4 backspace.

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'69 Ford Torino Formal Roof 302
Live for this!